You will need what is called a refractory fire brick (ask for the softer type fire brick)There are places online you can order them if you just do a search for them.There are some that are very hard and I dont have a clue how you could get a hole in one cause I have tried to no avail:banghead: but for the soft kind it's really easy to just drill through the length of the brick and you can kinda woller out the oval shape to the inside with a file or a piece of steel,the ones I have are kinda sandy/crumbley to the point I could break in half with my bare hands.Now I made the hole an oval shape about
1-1/2"x2-1/2"length wise all the way through and that way I can just block off one end for shorter blades or remove for longer blades,next on the side of the brick I drilled a hole just big enough for my torch tip.After I used mine for awhile I decided to throw together a little stand to hold my 1 brick forge that I really like heres a couple pics... Hope this helps.